Incompatible changes in ArangoDB 3.2

It is recommended to check the following list of incompatible changes before upgrading to ArangoDB 3.2, and adjust any client programs if necessary.

AQL

AQL breaking change in cluster: The SHORTEST_PATH statement using edge-collection names instead of a graph name now requires to explicitly name the vertex-collection names within the AQL query in the cluster. It can be done by adding WITH <name> at the beginning of the query.

Example:
```
FOR v,e IN OUTBOUND SHORTEST_PATH @start TO @target edges [...]
```
Now has to be:
```
WITH vertices
FOR v,e IN OUTBOUND SHORTEST_PATH @start TO @target edges [...]
```
This change is due to avoid dead-lock sitations in clustered case. An error stating the above is included.

REST API

Removed undocumented internal HTTP API:
- PUT /_api/edges
The documented GET /_api/edges and the undocumented POST /_api/edges remains unmodified.
change undocumented behavior in case of invalid revision ids in If-Match and If-None-Match headers from returning HTTP status code 400 (bad request) to returning HTTP status code 412 (precondition failed).
the REST API for fetching the list of currently running AQL queries and the REST API for fetching the list of slow AQL queries now return an extra bindVars attribute which contains the bind parameters used by the queries.

This affects the return values of the following API endpoints:
- GET /_api/query/current
- GET /_api/query/slow
The REST API for retrieving indexes (GET /_api/index) now returns the deduplicate attribute for each index
The REST API for creating indexes (POST /_api/index) now accepts the optional deduplicate attribute
The REST API for executing a server-side transaction (POST /_api/transaction) now accepts the optional attributes: maxTransactionSize, intermediateCommitCount, intermediateCommitSize
The REST API for creating a cursor (POST /_api/cursor) now accepts the optional attributes: failOnWarning, maxTransactionSize, maxWarningCount, intermediateCommitCount, satelliteSyncWait, intermediateCommitSize. skipInaccessibleCollections

JavaScript API

change undocumented behavior in case of invalid revision ids in JavaScript document operations from returning error code 1239 (“illegal document revision”) to returning error code 1200 (“conflict”).
the collection.getIndexes() function now returns the deduplicate attribute for each index
the collection.ensureIndex() function now accepts the optional deduplicate attribute

Foxx

JWT tokens issued by the built-in JWT session storage now correctly specify the iat and exp values in seconds rather than milliseconds as specified in the JSON Web Token standard.

This may result in previously expired tokens using milliseconds being incorrectly accepted. For this reason it is recommended to replace the signing secret or set the new maxExp option to a reasonable value that is smaller than the oldest issued expiration timestamp.

For example setting maxExp to 10**12 would invalidate all incorrectly issued tokens before 9 September 2001 without impairing new tokens until the year 33658 (at which point these tokens are hopefully no longer relevant).
ArangoDB running in standalone mode will commit all services in the javascript.app-path to the database on startup. This may result in uninstalled services showing up in ArangoDB if they were not properly removed from the filesystem.
ArangoDB Coordinators in a cluster now perform a self-healing step during startup to ensure installed services are consistent across all Coordinators. We recommend backing up your services and configuration before upgrading to ArangoDB 3.2, especially if you have made use of the development mode.
Services installed before upgrading to 3.2 (including services installed on alpha releases of ArangoDB 3.2) are NOT picked up by the Coordinator self-healing watchdog. This can be solved by either upgrading/replacing these services or by using the “commit” route of the Foxx service management HTTP API, which commits the exact services installed on a given Coordinator to the cluster. New services will be picked up automatically.
The format used by Foxx to store internal service metadata in the database has been simplified and existing documents will be updated to the new format. If you have made any changes to the data stored in the _apps system collection, you may wish to export these changes as they will be overwritten.
There is now an official HTTP API for managing services. If you were previously using any of the undocumented APIs or the routes used by the administrative web interface we highly recommend migrating to the new API. The old undocumented HTTP API for managing services is deprecated and will be removed in a future version of ArangoDB.
Although changes to the filesystem outside of development mode were already strongly discouraged, this is a reminder that they are no longer supported. All files generated by services (whether by a setup script or during normal operation such as uploads) should either be stored outside the service directory or be considered extremely volatile.
Introduced distinction between arangoUser and authorized in Foxx requests. Cluster internal requests will never have an arangoUser but are authorized. In earlier versions of ArangoDB parts of the statistics were not accessible by the Coordinators because the underlying Foxx service couldn’t authorize the requests. It now correctly checks the new req.authorized property. req.arangoUser still works as before. Endusers may use this new property as well to easily check if a request is authorized or not regardless of a specific user.

Command-line options changed

--server.maximal-queue-size is now an absolute maximum. If the queue is full, then 503 is returned. Setting it to 0 means “no limit”. The default value for this option is now 0.
the default value for --ssl.protocol has been changed from 4 (TLSv1) to 5 (TLSv1.2).
the startup options --database.revision-cache-chunk-size and --database.revision-cache-target-size are now obsolete and do nothing
the startup option --database.index-threads option is now obsolete
the option --javascript.v8-contexts is now an absolute maximum. The server may start less V8 contexts for JavaScript execution at startup. If at some point the server needs more V8 contexts it may start them dynamically, until the number of V8 contexts reaches the value of --javascript.v8-contexts.

the minimum number of V8 contexts to create at startup can be configured via the new startup option --javascript.v8-contexts-minimum.
added command-line option --javascript.allow-admin-execute

This option can be used to control whether user-defined JavaScript code is allowed to be executed on server by sending via HTTP to the API endpoint /_admin/execute with an authenticated user account. The default value is false, which disables the execution of user-defined code. This is also the recommended setting for production. In test environments, it may be convenient to turn the option on in order to send arbitrary setup or teardown commands for execution on the server.

The introduction of this option changes the default behavior of ArangoDB 3.2: 3.2 now by default disables the execution of JavaScript code via this API, whereas earlier versions allowed it. To restore the old behavior, it is necessary to set the option to true.

Users Management

It is no longer supported to access the _users collecction in any way directly, except through the official @arangodb/users module or the _apit/users REST API.
The access to the _users collection from outside of the arangod server process is now forbidden (Through drivers, arangosh or the REST API). Foxx services are still be able to access the _users collection for now, but this might change in future minor releases.
The internal format of the documents in the _users collection has changed from previous versions
The _queues collection only allows read-only access from outside of the arangod server process.
Accessing _queues is only supported through the official @arangodb/queues module for Foxx apps.

❮ Known Issues in 3.2 Version 3.1 ❯